Can anyone tell me what’s going on here? I made this model of a teacup, but when I set it smooth and / or subsurf it, some strange things happen to the model.
Why does that happen? (there were also other similar changes further down in the cup…)
Try selecting all (press a) in edit mode , then press w > choose remove doubles
Select all vertices, then CTRL+N>>Recalc normals outside. See if that works.
Friday13: Didn’t work. 
Hazza: “Removed 0 vertices”
I zoomed in at some of the problem areas and it seems some of the faces aren’t connected, I don’t know how that could’ve happened though…
Edit: It seemed kind of hopeless, so I started over again, but now, I see some strange stuff coming up in the render… buit not the same.
How come it looks like that?
Edit: Wow, ‘w->remove doubles’ worked on that, so thx I guess. 
Even though this was a small problem, and something that only arises as a problem to a newbie, knowing how to fix it has greatly improved my modeling.